This invention relates to water purification systems. More particularly, this invention relates to water purification systems incorporating ozone injection means.
Commonly known ozone water purification systems comprise the elements of an ozone gas generating apparatus, a water carrying tube including an ozone contact time segment, and a bubble separating column or chamber. The ozone generating apparatus typically comprises a cylindrical chamber through which atmospheric air containing diatomic oxygen is pumped or drawn. Radiation from a lamp capable of emitting intense ultraviolet light having a wave length of approximately 185 nanometers excites the diatomic oxygen within the chamber. As a result of such molecular excitation, a fraction of the diatomic oxygen within the chamber is split, producing free atoms of oxygen. As a result of their extremely high chemical reactivity, free oxygen atoms within the chamber rapidly react with the remaining intact oxygen, forming molecules having three atoms of oxygen. Molecules consisting of three oxygen atoms are commonly referred to as ozone or O3 gas.
Another commonly known means of producing ozone gas within such a chamber is to introduce closely spaced electrodes therein and to induce a sufficient electrical potential difference between the electrodes to produce electric discharge arcing. Diatomic oxygen molecules in close proximity with such electrical arcing similarly degrade into free oxygen atoms which quickly react with diatomic oxygen to form ozone gas.
In commonly known configurations of ozone water purification systems ozone rich air which emits from the ozone generator apparatus is introduced into a stream of water in need of purification, such water typically moving through a tube. Where the air within the ozone generating apparatus is pressurized by, for example, an air compressor, the output of the ozone generator may be introduced into the water carrying tube by means of a simple air line interlinking the output of the ozone generator and an aperture extending through the wall of the water carrying tube. Alternately, the air line may terminate at a venturi installed in line with the tube, creating a localized venturi effect at the output end of the air line. Use of a venturi allows the kinetic energy of water within the water carrying tube to perform work upon the air within the air line, drawing air from the ozone generator through the air line and into the stream of water.
Ozone carrying air which is either injected into the contaminated water stream or drawn into the stream by a venturi initially exists in the form of air bubbles. In order for the ozone gas to have a purifying effect upon the water, such gas must be dissolved into the water. Dissolution of the gas into the water necessarily occurs at the spherical surface tension boundaries between the gas and the water. A high solubility differential between common air components and ozone gas causes the ozone within such air bubbles to dissolve more quickly than other gases. Nevertheless, ozone carrying bubbles must remain immersed in water a sufficient length of time to achieve sufficient dissolution of ozone.
In commonly configured ozone water purification systems, the water carrying tube serves dual functions, both transporting water containing dissolved ozone to its desired destination, and providing an elongated immersion chamber where air bubbles containing ozone may remain in contact with the water a sufficient length of time for dissolution. In order for ozone dissolution to occur within the water carrying tube, the tube must have a sufficient length, i.e., an ozone contact time length. The contact length of the tube typically is approximately three feet in length. However, the length may vary between one foot and four feet depending upon variables such as rate of flow within the tube, turbulence and water temperature. Sharp turns within the tube or turbulence inducing baffles or screens installed within the bore of the water carrying tube may serve the function of breaking larger ozone carrying bubbles into smaller bubbles, increasing the overall surface area of the bubbles, and increasing the rate of dissolution of ozone.
Air bubbles injected by the ozone generating apparatus into the water carrying tube cease to serve a useful function upon reaching the end of the contact length of the tubing. At that point, substantially all ozone with the air bubbles is dissolved into the surrounding water, leaving residual bubbles consisting largely of normal atmospheric gases. In many circumstances, the continued presence of such gas bubbles within a water purification system is undesirable. For example, where the system recycles ozone bearing water in a feedback loop through a water pump, bubbles may cause the pump to lose its prime or cavitate. Also, it is often undesirable to introduce a stream of bubble carrying water directly into a tank of drinking water. Similarly, it is undesirable for air bubbles to emit from the water jets of a swimming pool. Thus, it is desirable to remove the air bubbles after dissolution of the ozone.
In order to remove air bubbles from a water purification system after dissolution of ozone, a bubble separator is often utilized, the bubble separator commonly comprising a hollow cylinder having an upper water input port, a lower water output port, and an upper off gassing vent. Typically, the water input port is continuous with the downstream end of the water carrying tube. Typically, the bubble separator is oblongated and is oriented so its long axis is vertical.
In operation, such a bubble separator removes air bubbles by reducing the velocities of currents of water within the bubble separator to a rate slow enough to allow bubbles to rise to the top of the bubble separator. The bubbles then emit as harmless atmospheric gases through the off gassing vent in the ceiling of the bubble separator, rather than continuing to flow downstream through the output end of the bubble separator. Preferably, the output flow of the bubble separator is adjusted to prevent over filling. Also preferably, a float valve or solenoid controlled valve installed within the off gassing vent assures that water will not escape from the system through the vent.
Where water bearing dissolved ozone gas is poured into a body of water such as, for example, a swimming pool, the ozone beneficially reacts with various contaminants. For example, ozone rapidly reacts with metal ions within the water, forming precipitants which may be removed through filtration. Ozone within water also degenerates or causes lysis of the cell walls of bacteria, killing the bacteria. Ozone within water also beneficially oxidizes and neutralizes sulfides, nitrates, cyanides, detergents, and pesticides. In all such cases, the efficacy of ozone in reacting with such contaminants is enhanced by reducing the average physical distance between contaminant organisms or molecules and the molecules of ozone within the water. In a large volume of water, such as a drinking water storage tank, spa, or swimming pool, the concentration of dissolved ozone becomes undesirably low, slowing the rate at which the ozone reacts with contaminants. To prevent such dilution of ozone concentration, it is desirable to first introduce the ozone carrying water into a reaction chamber having a smaller interior volume which maintains higher concentrations of ozone.
The instant invention eliminates the necessity of installing a separate concentration enhancing chemical reaction chamber by causing a bubble separator to additionally serve such function. Such effect is accomplished by applying a water level sensitive valve to the bubble separator""s output. Particularly, the water level sensitive controlled valve is adapted to cause the bubble separator to undergo hysteresis, continuously alternately collecting and discharging the water.
Several valve control means are capable of causing a vessel such as the above described bubble separator to continuously alternately fill and purge In an all mechanical example, a floating flap valve, such as is utilized to control the output from a common toilet tank, may be installed to alternately overlie and pivotally move from an output aperture within the floor of the bubble separator, such floating flap valve being mechanically linked to a buoy or float, the length of the linkage being calibrated to allow the float to buoyantly open such floating flap valve when the water level within the bubble separator reaches a desired upper level. A preferred electro-mechanical example comprises a float, a float carrying frame, an electric toggle switch, a power source, and an electric solenoid valve. In such exemplary electro-mechanical control assembly, the toggle switch is mounted upon the inner wall of the bubble separator so that its switch lever extends into the interior of the bubble separator, and so that its positive and negative electric contacts are accessible by lead wires extending through the wall of the bubble separator. The float carrying frame is preferably pivotally mounted upon the lever arm of the toggle switch. The float is preferably slidably mounted upon the frame so that as the float buoyantly rises, the float upwardly trips the toggle switch, and so that as the float sinks to a lower level, the weight of the float downwardly trips the toggle switch. Exterior to the bubble separator, the toggle switch forms a part of an electric circuit including the electric power source and the electric controlled valve, such valve preferably being a solenoid valve. Alternately, such valve may be actuated by an electric motor. Such a valve preferably has a spring actuated normally open position. Where the solenoid valve is normally open, the electric circuit is opened by the buoyant action of the float upon reaching the upper end of the frame, and the electric circuit is closed by the weight of the float upon reaching the lower end of the frame. Numerous other means, such as an electric water sensor controlled solenoid valve may be utilized to cause the water within the bubble separator to continuously alternately collect and discharge.
By continuously alternately collecting and discharging the water within the bubble separator, ozone within the water is allowed time to react with contaminants in a high concentration environment.
Accordingly, it is an object of the present invention to provide an ozone based water purification system which incorporates in series an ozone generating apparatus, an ozone contact time tubing segment, and a bubble separating chamber.
It is a further object of the present invention to provide such a system wherein the bubble separating chamber performs the dual functions of removing air bubbles from water to be purified, and serving as a low volume chemical concentration chamber.
Other objects and benefits of the present invention will become known to those skilled in the art upon review of the Detailed Description which follows, and upon review of the appended drawings.